Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending co...Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction （MI） and [Ca^2＋]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2＋]i induced by isoproterenol in normal ventricular myocytes （P 〉 0.05）, ICI118, 551 only significantly attenuated the rise of [Ca^2＋]i induced by isoproterenol at four weeks and eight weeks after MI （24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01）. Atenolol had suppressive effects only in the control group and the post-MI group of two weeks （P 〈 0.05）, and propranolol had suppressive effects in the control and all the three post-MI groups （P 〈 0.01）. Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2＋ overload initiated by sympathetic stimulation after MI.展开更多
The study was performed with seven groundnut varieties/genotypes and F1s derived from crossing in all possible combinations without reciprocal among the mentioned varieties/genotypes. The objective was to assess wheth...The study was performed with seven groundnut varieties/genotypes and F1s derived from crossing in all possible combinations without reciprocal among the mentioned varieties/genotypes. The objective was to assess whether low Ca2＋ content and Ca2＋/Na＋ ratio of leaf tissue or stem tissue determine salinity tolerance in terms of economic yield （kernel yield） in groundnut. It revealed that the varieties, “Binachinabadam-6”, “Binachinabadam-5” and the F1 G2 × G3 were most tolerant based on kernel yield under 8 dS/m and 10 dS/m salinity stresses. These two tolerant varieties and the F1 also showed lower Ca2＋ and Ca2＋/Na＋ ratios in leaf tissue, which indicated lower Ca2＋ and Ca2＋/Na＋ ratio of leaf tissue determined salinity tolerance in terms of kernel yield in Spanish type groundnut. These findings could be applied in future plant breeding applications for screening salt tolerant Spanish type groundnut genotypes.展开更多
文摘Objectives To investigate the effects of β2-adrenergic antagonist on cytosolic Ca^2 ＋ （[Ca^2＋ ]i） in ventricular myocytes from infarcted rat heart. Methods A ligature was placed around left anterior descending coronary artery of rat hearts. Rats in the control group were sham-operated. Cardiomyocytes were dissociated at two, four, eight weeks after myocardial infarction （MI） and [Ca^2＋]i was measured via fura-2 fluorescence. The response of cardiomyocytes to isoproterenol in presence or absence of betal-adrenergic antagonist atenolol, beta2-adrenergic antagonist ICI118, 551 or non-selective β1, 2- adrenergic antagonists propranolol was examined. Results The followings were found that ICI 118, 551 had no significant effects on the rise of [Ca^2＋]i induced by isoproterenol in normal ventricular myocytes （P 〉 0.05）, ICI118, 551 only significantly attenuated the rise of [Ca^2＋]i induced by isoproterenol at four weeks and eight weeks after MI （24.5%±5.7% vs 57.8% ± 13.2%, P〈 0.01; 12.2%±7.9% vs 44.6%±11.3%, P〈 0.01）. Atenolol had suppressive effects only in the control group and the post-MI group of two weeks （P 〈 0.05）, and propranolol had suppressive effects in the control and all the three post-MI groups （P 〈 0.01）. Conclusions Beta2-adrenergic antagonist ICI118, 551 may exert negative effects on Ca^2＋ overload initiated by sympathetic stimulation after MI.
文摘The study was performed with seven groundnut varieties/genotypes and F1s derived from crossing in all possible combinations without reciprocal among the mentioned varieties/genotypes. The objective was to assess whether low Ca2＋ content and Ca2＋/Na＋ ratio of leaf tissue or stem tissue determine salinity tolerance in terms of economic yield （kernel yield） in groundnut. It revealed that the varieties, “Binachinabadam-6”, “Binachinabadam-5” and the F1 G2 × G3 were most tolerant based on kernel yield under 8 dS/m and 10 dS/m salinity stresses. These two tolerant varieties and the F1 also showed lower Ca2＋ and Ca2＋/Na＋ ratios in leaf tissue, which indicated lower Ca2＋ and Ca2＋/Na＋ ratio of leaf tissue determined salinity tolerance in terms of kernel yield in Spanish type groundnut. These findings could be applied in future plant breeding applications for screening salt tolerant Spanish type groundnut genotypes.
